| 摘要 |
<p>PROBLEM TO BE SOLVED: To simplify and thin a stage device and to improve the precision of the attachment/detachment of the mounted object of a wafer and a reticle, by adjusting a beam diameter or the axial direction position of a beam with which a position measuring mirror is irradiated in accordance with shift in a vertical axial direction against the direction of a specified face. SOLUTION: Even if a gate stage 1 moves to the direction of Z against an XY stage 6 byΔZ, an automatic variable diaphragm 302 operates lest the beam 8 of a laser interference device is cut, and the beam diameter is converged. If the position measuring mirror 7a when the gate stage 1 is positioned to a lowermost point is irradiated at the time of exchanging the wafer, the angle of a parallel plate can be varied and the height of the beam can be changed. When the gate stage 1 is in the position of the lowermost point, for example, the parallel plate is inclined to a specified angle and the beam 8 can be lowered byΔd by adding a mechanism for automatically inclining the parallel plate.</p> |
